Gimbal mountings for antennas, optical devices and the like have been made in many different configurations. One particular type has an outer gimbal in the form of a yoke which rotates in an arcuate support about one axis, and carries an inner gimbal which rotates in the yoke about another axis. In one arrangement the outer gimbal is driven by one motor and the inner gimbal is driven by a separate motor mounted on the inner gimbal. This adds considerable weight to the moving components and, in most instances, requires balancing means for smooth operation.
In another arrangement, such as shown in U.S. Pat. No. 2,654,031, two motors are connected to a differential drive mechanism to drive both gimbals, either selectively or in various combinations of motions. This mechanism is a complex arrangement using a cable to drive the outer gimbal, with a connection to the inner gimbal through a differential gear mechanism at one end and a reversing gear at the other end. This also results in considerable unnecessary weight being carried on the moving components.